If you have a box of needles you should have many duplicates. Knit the scarf with needles you like then replace them with some you don't like. In some you could leave one needle in the work and use the other to attach the ball of yarn to the middle of the scarf. A small touch of glue on the back side of first and last stitch on the needle should hold the stitches on the needle. You could also use point protectors, little rubber caps that go over the point of the needle or a small rubber band wrapped on end of the needle.
On another you could leave both needles in work and use a little glue to hold the stitches.